876 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



many places as rapid as the Rhine near Bonn, its rapidity being 1^ to 2 

 meters a second. 



The bottom of this turbulent ocean is mainly composed of quartz-sand. 

 Farther away from the strong currents the so-called "sc/iZicl" is de- 

 posited a clayey mud containing organic matter ; this is the case at 

 many points of the eastern coast of Sylt and on the coast of the mainland. 

 On the slopes between the " Watten " and the deep channels the bottom 

 is for great distances covered with coarse gravel, small and large stones, 

 and shells. In such places we find, besides many other marine animals, 

 colonies of oysters, so-called oyster-beds. As the water is full of little 

 floating particles of clayey mud, these oyster-beds cannot be seen ; their 

 location, however, has been known to the fishers for centuries ; and they 

 find them by steering their vessels toward high points of the coast and 

 of the islands. The oysters are caught with drag nets, consisting of an 

 iron frame from which depends a bag composed of iron rings and coarse 

 yarn, with an opening measuring about 1 meter. The whole net weighs 

 about 60 pounds. It is generally drawn along for 5 to 7 minutes ; then 

 two or three men draw it up and throw its contents on the deck of the 

 vessel. This consists of old oyster-shells, different animals and plants, 

 and live oysters, which are picked out, freed from all animal or vege- 

 table matter adhering to the shells, and then shipped to the markets. 



In no part of the " Watten Sea " do the oysters lie on rocky bottom. 

 The best bottom for them is that which is composed of old oyster-shells. 

 It is an erroneous idea that the oysters stick to the bottom of the sea, 

 or that they lie close together or in layers. In good Schleswig-Holstein 

 oyster-beds the net has to be drawn over a space of 1 to 3 meters square 

 and even larger in order to get a single full-sized oyster. 



The number of our oyster-beds is 47, and their extent varies very 

 much. The largest extends one-half German mile (about 2| English 

 miles) in length. Most of them, however, are not so long, and only a few 

 hundred feet broad. Although all the beds are located within a ter- 

 ritory 10 German miles long and 3 German miles broad, the quality of 

 the oysters varies very much. If all the 47 beds were put together, 

 they would not cover the hundredth part of that portion of the " Watten 

 Sea'''' which always remains under water. What is the cause of this? Is 

 there a lack of young oysters to occujiy all the vacant spaces between 

 the beds *? I cannot suppose that this is the case, and my reasons are 

 the following : 



The total number of full-grown oysters in our beds may be about 

 5,000,000. According to investigations made by me iu 18G9, at least 44 

 per cent, of all the full grown oysters produce young ones; and as 

 every full-grown, pregnant oyster produces at least 1,000,000 young ones, 

 the number of young oysters produced during the breeding season, 

 which generally lasts from June till August, would be 2,200,000,000,000, 

 sufficient to make the whole ^^ Watten Sea''"' one continuous oyster-bed j 



